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Flashcards in antimicrobial resistance Deck (36)
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1
Q
Where is ampC info located?
A
Chromosomally
2
Q
ampC is resistance to:
A
beta lactamases: penicillin and cephalosporin (cannot be inhibited by beta lactamase inhibitors)
3
Q
Which 2 organisms can have ampC?
A
EnterobacterPseudomonas
4
Q
List 3 enterobacteriaceae
A
EnterobacterE coliKlebsiella
5
Q
2 drugs that can induce amp C
A
cefazolinampicilin
6
Q
ESBL is located in?
A
plasmid
7
Q
amp expression can be _____ or _____
A
inducible or constitutive
8
Q
ESBL is in which 2 bugs?
A
E. Coli and Klebsiella
9
Q
b-lactamase inhibitor's effect onESBL and ampC
A
Can help with ESBL but cannot help with amp C
10
Q
Who can acquire erm and msr?
A
Staph AureusStrep Pneumo
11
Q
erm is inducible by?
A
only by macrolides
12
Q
erm affects which two drugs
A
macrolides (Erythromycin induced) and clindamycin
13
Q
Why are ERM and ampC important
A
single mutation --> change to consitutive on.Can occur DURING therapy
14
Q
How does erm work?
A
dimethylation of 23S rRNA.Macrolides cannot bind to 23s rRNA (part of 50S)
15
Q
How does msr gene work?
A
drug efflux
16
Q
what does erm-D-test tell you?
A
If bug has erm (inducible) or efflux resistence.
17
Q
What can you treat with if bug has msr (efflux resistance) (clindamycin/macrolides)
A
Clindamycin - yesMacrolides - no
18
Q
What can you treat with if bug has erm (inducible)?(clindamycin/macrolides)
A
Do not use clindamycinDo not use Macrolides
19
Q
Who has narrow spectrum b-lactamase?
A
S. Aureus (MSSA)E.coli TEM-1Klebs Pneumo SHV1
20
Q
narrow spectrum b-lactamse resists which drugs?
A
penicillinAmpicillin
21
Q
ESBL (plasmids) resists which drugs?
A
Penicillins + cephalosporins
22
Q
_____ and ______ both resists penicillin and cephalosporin?
A
ESBL and ampC
23
Q
MRSA resistance (gene: mecA) due to?
A
PBP --> PBP2a (low affinity)
24
Q
VRE has two genes ____ and ____ and located in ______
A
van A, vanB, plasmid
25
Q
How does vancomysin work?
A
Bind to precursor for cell wall
26
Q
How does VRE have resistance?
A
Precursor is changed to D-ala-D-lac (from D-ala-D-ala)
27
Q
How does N. Gonorrhoeae have resistance?
A
altered PBP
28
Q
3 main ways antibiotic resistance
A
1. inactivate/modify drug2. Alter drug target3. reduce ability of drug to get to target
29
Q
E. Coli TEM-1 vs E. Coli
A
gained penicillimase from plasmid
30
Q
Ecoli's TEM1 vs Klebsiella SHV1 location difference
A
Ecoli TEM1 - plasmidKlebsilla SHV1 - chromosomal
31
Q
Two plasmid that causes resistance of penicillin, cephalosporin, AND carbapenem?
A
KPCNDM1
32
Q
Aminoglycosides resistance occurs how?
A
Inactivating/modifying drug:N – acetylation, O-nucleotidylation, O-phosphorylation
33
Q
Two ways altered PBP?
A
mecA (MRSA) - PBP2aMosaic PBP (strp pneumoniae/N. gonorrhoeae)
34
Q
VISA (vancomycin - intermediate - susceptibility S. aureus) have two major diff from sensitive strains
A
1. thicker layer of peptidoglycan2. Less cross linking (absorbs vanco)
35
Q
_____ of DNA gyrase and ____ of topo IV have quinolone resistance determining region (QRDR)
A
GyrA & ParC
36
Q
QRDR (quinolone resistance determining region) effect
A
enzyme less sensitive to inhibition by quinolones --> reduce drug/target affinity